If you use or are considering Essure, an irreversible form of birth control, you’ll want to hear about this: The FDA has announced that it will require a new "black box" warning for the contraceptive implant. The black box is the strongest warning that the FDA issues, and indicates that research has found that the product comes with a significant risk of serious or life-threatening effects.

The government agency decided to issue the warning after it heard complaints from 5,000 women that Essure caused unintended pregnancies, miscarriages, stillbirths, and severe pain and bleeding. Some women also say it broke apart inside them.

“While the FDA believes Essure remains an appropriate option for the majority of women seeking a permanent form of birth control, some women may be at risk for serious complications,” the FDA said in a press announcement released earlier this week. “These may include persistent pain, perforation of the uterus or fallopian tubes from device migration, abnormal bleeding, and allergy or hypersensitivity reactions.”

The move will require warning language on the labeling for Essure, and will also result in a checklist for patients to go over with their doctors and sign before receiving an implant of this kind. The FDA is also requiring Bayer, the company that makes Essure, to study more than 2,000 women (including those who don’t use Essure) for at least three years to see whether additional public safety measures need to be taken.

Essure is a form of birth control in which coils are placed into a woman’s fallopian tubes. Scar tissue then forms around the coils, which prevents sperm from reaching a woman’s eggs and fertilizing them (in theory, keeping her from becoming pregnant).

Women who use other forms of contraceptive implants may be nervous about the news, but ob/gyn Alyssa Dweck, M.D., an assistant clinical professor at the Mount Sinai School of Medicine, says they shouldn’t be. While both Essure and intrauterine devices (IUDs) involve placing implants inside a woman, Dweck calls Essure and IUDs “night and day.”

According to the Essure website, the product should not be considered reversible and is designed for women who are “certain you do not want to have more children.” IUDs, on the other hand, are reversible. Essure is also placed where the fallopian tubes and uterus meet, explains Lauren Streicher, M.D., an associate professor of clinical obstetrics and gynecology at Northwestern University Feinberg School of Medicine, while IUDs are placed in the uterus.

IUDs come with some risks, like a slightly higher risk of miscarriage if a woman gets pregnant while using the device and a slight risk of having an ectopic pregnancy, but “we’re talking miniscule risk,” Dweck says. There’s also a chance that an IUD may puncture the uterine wall when it’s placed inside a woman, but Streicher calls this a “very, very rare occurrence.”

Overall, Dweck considers IUDs to be “extraordinarily safe when used in the right person.” For example, women who experience heavy periods shouldn’t use the copper implant (also known as Paragard) because it may cause heavier-than-normal periods. However, they may want to consider a hormonal IUD like Mirena, which is known to help with heavy periods.

If you have an IUD and are happy with it, Streicher says there’s no reason to worry about the latest warning. “None of the concerns about Essure apply to an IUD,” she says. And, if you’re happy with Essure now, you’ll likely to continue to be. “For many women, Essure is a godsend,” Streicher says. “But for some, there are complications.”